Methods and apparatus for storage and/or introduction of implant for hollow anatomical structure

ABSTRACT

One embodiment of the apparatus comprises a housing with a sheath portion projecting distally therefrom. The sheath portion has a sheath with a lumen, and a bearing surface in the sheath lumen or aligned with the sheath lumen, and located at or near a distal end of the sheath. The implant is at least partially positioned in the apparatus, and comprises an implant body and a tether connected to the implant body. The tether extends from the implant body distally within the sheath portion and around the bearing surface, where the tether changes direction, and extends back proximally from the bearing surface along and within the sheath portion. The apparatus is configured to move the first tether portion proximally and thereby draw the implant body distally along and within the sheath lumen.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application Ser. No.61/357,095, filed on Jun. 22, 2010, and provisional application Ser. No.61/357,952, filed on Jun. 23, 2010. The entire contents of each of thepriority applications are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to occluding hollow anatomical structures.

BACKGROUND

Referring to FIG. 1, the human venous system of the leg A comprises thesuperficial venous system, shown in white, and the deep venous system,shown in black, with perforating veins connecting the two systems. Thesuperficial system includes the long or great saphenous vein B and thesmall saphenous vein C. The deep venous system includes the anterior andposterior tibial veins D, E, which unite to form the popliteal vein F,which in turn becomes the femoral vein G when joined by the shortsaphenous vein C. The femoral vein G and the great saphenous vein B joinat the sapheno-femoral junction H.

The venous system contains numerous one-way valves for directingantegrade blood flow back to the heart. When an incompetent valve is inthe flow path, the valve is unable to close, and retrograde flow of theblood away from the heart cannot be stopped. When a venous valve fails,increased strain and pressure occur within the lower venous sections andoverlying tissues, sometimes leading to additional, distal valvularfailure. Two venous conditions or symptoms that often result from valvefailure are varicose veins and more symptomatic chronic venousinsufficiency. Current treatments of venous insufficiency includesurgical procedures such as vein stripping, vein-segment transplant, andligation by ablation.

Vein stripping typically consists of tying off, or ligating, andremoving the saphenous vein. Vein segment transplant has been employedin certain organ transplant procedures; however, it is not generallyemployed in the superficial venous system in humans. Ligation byablation involves the cauterization or coagulation of vascular luminausing thermal energy applied through a delivery device. Energyintroduced into the vein lumen causes the vein wall to shrink incross-sectional diameter or completely collapse, thereby reducing orcompletely blocking blood flow through the vein.

An alternative treatment involves placement of an occluding implant inthe hollow anatomical structure, such as the great saphenous vein. As anexample, the implant can be a fibrous body, optionally textured toimpart bulk. The implant causes a partial occlusion of the hollowanatomical structure, followed by a complete or substantially completeocclusion, such as by formation of an organic fibrotic occlusionresulting from the body's natural foreign body healing response.

SUMMARY

The various embodiments of the present methods and apparatus haveseveral features, no single one of which is solely responsible for theirdesirable attributes. Without limiting the scope of the presentembodiments as expressed by the claims that follow, their more prominentfeatures now will be discussed briefly. After considering thisdiscussion, and particularly after reading the section entitled“Detailed Description,” one will understand how the features of thepresent embodiments provide the advantages described herein.

One embodiment comprises an apparatus for delivering an implant. Theapparatus comprises a housing, a sheath portion projecting distally awayfrom the housing, the sheath portion having a sheath with a sheathlumen, and a bearing surface in the sheath lumen or aligned with thesheath lumen, and located at or near a distal end of the sheath. Theimplant is at least partially positioned in the apparatus, and comprisesan implant body and a tether connected to the implant body. The tetherhas a first portion that extends from the implant body distally withinthe sheath portion and around the bearing surface, where the tetherchanges direction, and extends back proximally, as a second portion,from the bearing surface along and within the sheath portion. Theapparatus is configured to move the first tether portion proximally andthereby draw the implant body distally along and within the sheathlumen.

Further optional features and variations of this embodiment arepresented in the following paragraphs. The present disclosurecontemplates and includes employing these optional features andvariations in the third embodiment (or in any other embodimentsummarized or described herein), either alone or in any feasiblecombination of two or more such optional features and variations.

The implant body can optionally be bioabsorbable and comprise acollection of bioabsorbable fibers. As still further options, the tethercan be bioabsorbable and inelastic. As still further options, theimplant body can be radially self-expanding.

The apparatus can optionally further comprise a reel that is coupled tothe tether and configured to move the first tether portion proximally,and thereby draw the implant body distally along and within the sheathlumen.

The sheath portion can optionally further comprise an inner member thatextends distally along and within the sheath lumen, and the bearingsurface is positioned at or near a distal end of the inner member. Asstill further options, the inner member can comprise an inner memberlumen extending within the inner member, and the first tether portioncan extend along and within the inner member lumen. As still furtheroptions, the sheath can be retractable proximally to expose the innermember. As still further options, the apparatus can further comprise asheath parting member that projects into the sheath lumen through anopening in a sidewall of the sheath, wherein the sheath parting memberis configured to part the sidewall of the sheath as the sheath isretracted proximally. As still further options, the sheath partingmember can comprise a sharpened blade that cuts through the sheathsidewall as the sheath is retracted. As still further options, thesheath sidewall can have a score line and the sheath parting member cancomprise a post or unsharpened wedge that splits the sheath sidewallalong the score line as the sheath is retracted. As still furtheroptions, the inner member can comprise an inner member lumen extendingwithin the inner member, and the first tether portion can extend alongand within the inner member lumen; and a proximal portion of the innermember can comprise a lateral projection that turns and extends radiallyoutward to pass out of the sheath lumen, at a location proximal of thesheath parting member, such that the lateral projection of the innermember can be positioned between two parted portions of the sheathsidewall as the sheath is retracted proximally and the sheath sidewallis parted. As still further options, the tether can passes through thelateral projection of the inner member such that the inner memberprevents contact between the sheath sidewall and the tether as thesheath is retracted proximally and the sheath sidewall is parted.

Another embodiment comprises an apparatus for delivering an implant. Theapparatus comprises a housing; and a sheath portion extending distallyaway from the housing, the sheath portion having a sheath with a sheathlumen. The implant comprises an implant body and a tether connected tothe implant body, and the implant has a first position in which theimplant body is at least partially located within the housing, and thetether extends distally along and within the sheath portion, and turnsto extend back proximally along and within the sheath portion. Theapparatus further comprises a reel that is configured to wind the tetherand thereby draw the implant body distally along and within the sheathlumen to a second position.

Further optional features and variations of this embodiment arepresented in the following paragraphs. The present disclosurecontemplates and includes employing these optional features andvariations in the fourth embodiment (or in any other embodimentsummarized or described herein), either alone or in any feasiblecombination of two or more such optional features and variations.

The sheath portion can optionally be sized and configured forpercutaneous insertion into a blood vessel.

The implant body can optionally be self-expanding, and the implant bodycan be in an expanded configuration when the implant is in the firstposition. As still further options, the implant body can be stored inthe housing when the implant is in the first position, and no portion ofthe implant body can be in the sheath lumen. As still further options,the implant body can be bioabsorbable and comprise a bundle of fibers.As still further options, the implant body can be in a compressedconfiguration when the implant is in the second position.

The sheath portion can optionally further comprise an inner memberextending along and within the sheath lumen, the inner member providinga bearing surface at or near the distal end of the sheath, within oraligned with the sheath lumen. As still further options, the tether canhave a first portion that extends from the implant body distally withinthe sheath portion and around the bearing surface, where the tether canchange direction, and extend back proximally, as a second portion, fromthe bearing surface along and within the sheath portion. As stillfurther options, the inner member can comprise an inner member lumenextending within the inner member, and the first tether portion canextend along and within the inner member lumen, proximally toward thereel. As still further options, the sheath can be retractable proximallyto expose the inner member. As still further options, the apparatus canfurther comprise a sheath parting member that projects into the sheathlumen through an opening in a sidewall of the sheath, wherein the sheathparting member is configured to part the sidewall of the sheath as thesheath is retracted proximally. As still further options, the sheathparting member can comprise\ a sharpened blade that cuts through thesheath sidewall as the sheath is retracted. As still further options,the sheath sidewall can have a score line and the sheath parting membercan comprise a post or unsharpened wedge that splits the sheath sidewallalong the score line as the sheath is retracted. As still furtheroptions, the inner member can comprise an inner member lumen extendingwithin the inner member, and the first tether portion can extends alongand within the inner member lumen; and a proximal portion of the innermember can comprise a lateral projection that turns and extends radiallyoutward to pass out of the sheath lumen, at a location proximal of thesheath parting member, such that the lateral projection of the innermember is positioned between two parted portions of the sheath sidewallas the sheath is retracted proximally and the sheath sidewall is parted.

Another embodiment comprises apparatus for delivering an implant. Theapparatus comprises a housing, an outer sheath projecting distally awayfrom the housing, the outer sheath having an outer sheath lumen, and aninner sheath projecting distally away from the housing at leastpartially within the outer sheath lumen, the inner sheath having aninner sheath lumen. The implant is at least partially positioned in theapparatus, and comprises an implant body and a tether connected to theimplant body. The apparatus is configured to advance the implant bodydistally within the inner sheath lumen without relative movement of theouter sheath and the inner sheath.

Another embodiment comprises a method of preparing a vascular implantfor subsequent deployment into a blood vessel, the implant having animplant body and a tether connected to the implant body. The methodcomprises moving the implant body from a first position, distally alongand within a lumen of a sheath that is sized and configured forpercutaneous insertion into a blood vessel, to a second position in adistal portion of the sheath lumen. Moving the implant body to thesecond position comprises drawing a portion of the tether proximally byapplying force to the tether at a location outside of the sheath andproximal of the second position.

Further optional features and variations of this embodiment arepresented in the following paragraphs. The present disclosurecontemplates and includes employing these optional features andvariations in the fifth embodiment (or in any other embodimentsummarized or described herein), either alone or in any feasiblecombination of two or more such optional features and variations.

Applying force to the tether can optionally comprise winding the tetheronto a reel. As still further options, the method can further comprisechanging a direction of force applied by the tether with a bearingsurface around which the tether turns, the bearing surface being locatedat or near a distal end of the sheath. As still further options, movingthe implant body to the second position can comprise compressing theimplant body while advancing it from the first position into a proximalportion of the sheath lumen. As still further options, the implant bodycan be self-expanding, and the implant body can be in an expandedcondition when in the first position. As still further options, thefirst position can comprise a storage position within a deliveryapparatus. As still further options, the method can further compriseinserting the sheath into a blood vessel and moving the implant body tothe second position while the sheath is inside the blood vessel.

Another embodiment comprises a method of delivering into a hollowanatomical structure (HAS) a bioabsorbable implant having an implantbody and a tether connected to the implant body. The method is performedwith the assistance of a delivery apparatus having a sheath assemblywith an outer sheath and an inner member extending along an inner lumenof the outer sheath to a distal end portion of the inner member, whichinner member distal end portion forms a bearing surface near a distalend of the outer sheath. The tether includes a distally-extendingportion that extends distally from the implant body along and within theouter sheath lumen, and turns around the bearing surface to form aproximally-extending portion that extends proximally from the bearingsurface along and within the sheath assembly. The method comprisesinserting the sheath assembly into the HAS, wherein inserting the sheathassembly comprises inserting the outer sheath and inner membersimultaneously; moving the implant body distally along and within theouter sheath lumen by moving the proximally-extending portion of theimplant tether proximally, so that a distal portion of the implant bodyadvances to a distal portion of the outer sheath; and withdrawing theouter sheath from the inner member and the implant body, while holdingthe implant body in its distally-advanced position with the inner memberand the tether.

Further optional features and variations of this embodiment arepresented in the following paragraphs. The present disclosurecontemplates and includes employing these optional features andvariations in the first embodiment (or in any other embodimentsummarized or described herein), either alone or in any feasiblecombination of two or more such optional features and variations.

Inserting the sheath assembly into the HAS can optionally compriseinserting the sheath assembly through a tissue tract extending from theskin surface to the HAS, and the method can optionally further comprisesevering the tether and withdrawing the inner member from the HAS, andleaving the implant in a state wherein the implant body resides withinthe HAS and the tether extends from a distal end of the implant body andinto the tissue tract, thereby facilitating anchoring of the implantbody with the tether.

Inserting the sheath assembly into the HAS can optionally compriseinserting the sheath assembly through a tissue tract extending from theskin surface to HAS, and the method can optionally further comprisesevering the tether and withdrawing the inner member from the HAS, andleaving the implant in a state wherein the implant body resides withinthe HAS, and the tether and the implant body extend from the HAS intothe tissue tract, thereby facilitating anchoring of the implant bodywith the tether.

The method can optionally further comprise severing the tether andwithdrawing the inner member from the HAS, leaving the implant body andtether in the HAS, and allowing the implant body to engage an inner wallof the HAS. As still further options, the inner member can comprise aninner sheath having an internal lumen, and the proximally-extendingportion of the tether can extend along and within the inner sheathlumen; and withdrawing the inner member from the HAS can compriseallowing the tether to slide out of the inner sheath lumen as the innermember is withdrawn. As still further options, the HAS can be a bloodvessel, and the method can further comprise occluding the blood vesselwith the implant.

The outer sheath can optionally have a sidewall, and the method canfurther comprise parting the sidewall of the outer sheath whilewithdrawing the outer sheath. As still further options, parting thesidewall of the outer sheath can comprise forming a longitudinal openingin the sidewall, thereby allowing the tether to pass through thesidewall opening as the outer sheath is withdrawn.

The method can further optionally comprise holding the deliveryapparatus in a first hand of a user while actuating the deliveryapparatus with the first hand to cause the implant body to move distallyalong and within the outer sheath lumen. As still further options,actuating the delivery apparatus with the first hand can comprisecausing the implant body to move to a distal-most position within theouter sheath where a distal end of the implant body is near a distal endof the outer sheath. As still further options, the method can compriseholding and operating an ultrasound probe with a second hand of the userwhile holding the delivery apparatus with the first hand. As stillfurther options, the method can comprise actuating the deliveryapparatus with the first hand while holding and operating the ultrasoundprobe with the second hand.

Moving the proximally-extending portion of the tether proximally canoptionally comprise winding the tether onto a reel.

Another embodiment comprises a method of delivering into a hollowanatomical structure (HAS) an implant having an implant body and atether connected to the implant body. The method is performed with theassistance of a delivery apparatus having a sheath portion with a sheathand a bearing surface near a distal end of the sheath, wherein thesheath has an inner lumen and the tether includes a distally-extendingportion that extends distally from the implant body along and within thesheath portion, and turns around the bearing surface to form aproximally-extending portion that extends proximally from the bearingsurface along and within the sheath portion. The method comprisesinserting the sheath portion into the HAS; moving the implant bodydistally along and within the sheath lumen by moving theproximally-extending portion of the implant tether proximally, so that adistal portion of the implant body advances to a distal portion of thesheath; and withdrawing the sheath from the implant body, while holdingthe implant body in its distally-advanced position with the tether.

Further optional features and variations of this embodiment arepresented in the following paragraphs. The present disclosurecontemplates and includes employing these optional features andvariations in the second embodiment (or in any other embodimentsummarized or described herein), either alone or in any feasiblecombination of two or more such optional features and variations.

The sheath portion can optionally comprise an outer sheath and an innermember which extends distally within the outer sheath to a distalportion of the outer sheath; the inner member can form the bearingsurface near a distal end of the inner member; and holding the implantbody in its distally-advanced position can comprise holding the implantwith the tether and the inner member. As still further options, theinner member can comprise an inner sheath having an internal lumen, andthe proximally-extending portion of the tether can extend along andwithin the inner sheath lumen; and the method can further comprisewithdrawing the inner member from the HAS while allowing the tether toslide out of the inner sheath lumen as the inner member is withdrawn.

Inserting the sheath portion into the HAS can optionally compriseinserting the sheath portion through a tissue tract extending from theskin surface to the HAS; and the method can further comprise severingthe tether and leaving the implant in a state wherein the implant bodyresides within the HAS and the tether extends from a distal end of theimplant body and into the tissue tract, thereby facilitating anchoringof the implant body with the tether.

Inserting the sheath portion into the HAS can optionally compriseinserting the sheath portion through a tissue tract extending from theskin surface to the HAS; and the method can further comprise severingthe tether and leaving the implant in a state wherein the implant bodyresides within the HAS and the tether and the implant body extend fromthe HAS and into the tissue tract, thereby facilitating anchoring of theimplant body with the tether.

The method can further optionally comprise severing the tether, leavingthe implant body and tether in the HAS, and allowing the implant body toengage an inner wall of the HAS.

The HAS can optionally be a blood vessel; and the method can furthercomprise occluding the blood vessel with the implant.

The sheath can optionally have a sidewall; and the method can furthercomprise parting the sidewall of the sheath while withdrawing thesheath. As still further options, Parting the sidewall of the sheath cancomprise forming a longitudinal opening in the sidewall, therebyallowing the tether to pass through the sidewall opening as the outersheath is withdrawn.

The method can further optionally comprise holding the deliveryapparatus in a first hand of a user while actuating the deliveryapparatus with the first hand to cause the implant body to move distallyalong and within the sheath lumen. As still further options, actuatingthe delivery apparatus with the first hand can comprise causing theimplant body to move to a distal-most position within the sheath where adistal end of the implant body is near a distal end of the outer sheath.As still further options, the method can further comprise holding andoperating an ultrasound probe with a second hand of the user whileholding the delivery apparatus with the first hand. As still furtheroptions, the method can further comprise actuating the deliveryapparatus with the first hand while holding and operating the ultrasoundprobe with the second hand.

Moving the proximally-extending portion of the tether proximally canoptionally comprise winding the tether onto a reel.

Inserting the sheath portion into the HAS can optionally be performedbefore advancing the implant body to the distal portion of the sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a human leg and portions of the deep andsuperficial venous systems;

FIG. 2 is an elevation view of an embodiment of an implant for occludinga hollow anatomical structure, such as a vein in the venous systemsshown in FIG. 1;

FIG. 3 is an elevation view of a system according to one embodimentcomprising the implant of FIG. 2 and an embodiment of an apparatus forstorage and/or introduction of the implant into a hollow anatomicalstructure;

FIG. 4 is a perspective view of a right housing shell of the apparatusof FIG. 3;

FIG. 5 is a perspective view of a left housing shell of the apparatus ofFIG. 3;

FIG. 6 is a cross-sectional view through the apparatus from FIG. 3 withthe apparatus sectioned at line “VI-VI” for clarity;

FIG. 7 is a front view of the apparatus of FIG. 3 with the housingsectioned at line “VII-VII” for clarity;

FIG. 8 is a close-up view of a portion of FIG. 6 to illustrate a tethercutting assembly and a sheath cutting assembly of the apparatus; asheath assembly and the implant are not shown for clarity;

FIG. 9 is an enlarged sectional view of the sheath assembly,particularly the distal and proximal ends of the sheath assembly, of theapparatus of FIG. 3 and the tether of the implant of FIG. 2;

FIG. 10 is a perspective view of the distal end of an inner sheath ofthe sheath assembly from FIG. 9; the tether is not shown for clarity;

FIG. 11 is a close-up cross-sectional view through the apparatus fromFIG. 3 to illustrate the assembly of the sheath assembly from FIG. 8with the housing of the apparatus from FIG. 3 and the path of the tetherof the implant of FIG. 2 through the housing;

FIGS. 12-15 provide sectional views of a body of the implant of FIG. 2in storage, first introduction, second introduction, and implantationconditions, respectively;

FIGS. 16-29 illustrate various exemplary stages of a method of use ofthe system according to one embodiment:

FIG. 16 illustrates the leg of FIG. 1 with the sheath assembly of FIG. 3located in the greater saphenous vein of the leg;

FIG. 17 is an enlarged view of the region labeled “XVII” in FIG. 16;

FIG. 18 is a view similar to FIG. 16, illustrating the actuation of anintroducer assembly of the apparatus of FIG. 3;

FIG. 19 is a view similar to FIG. 17 illustrating the forces on thetether of the implant of FIG. 2 during actuation of the introducerassembly;

FIG. 20 is a view similar to FIG. 11 during advancement of the implantof FIG. 2 through the sheath assembly of FIG. 3;

FIG. 21 is a view similar to FIG. 20 during further advancement of theimplant of FIG. 2 through the sheath assembly of FIG. 3;

FIG. 22 is a view similar to FIG. 18 after removal of an outer sheath ofthe sheath assembly from the apparatus;

FIG. 23 is a schematic underside view of the sheath cutting assemblyfrom FIG. 8 to illustrate the cutting of the outer sheath during removalof the outer sheath of the sheath assembly from the apparatus;

FIG. 24 is a view similar to FIG. 19 during retraction of the outersheath of the sheath assembly from the greater saphenous vein;

FIG. 25 is a view similar to FIG. 24 after removal of the outer sheathof the sheath assembly from the greater saphenous vein;

FIG. 26 is a view similar to FIG. 8, but with the sheath shown, duringcutting of the tether of the implant of FIG. 2;

FIG. 27 is a view similar to FIG. 25 illustrating the implant in thegreater saphenous vein after removal of the inner sheath from thegreater saphenous vein;

FIG. 28 illustrates the leg after implantation of the implant in thegreater saphenous vein; and

FIG. 29 is a plan view of the exterior region of the leg labeled “XXIX”in FIG. 28.

DETAILED DESCRIPTION

The disclosed embodiments relate generally to a method and apparatus forstorage and/or introduction of an implant into a hollow anatomicalstructure (HAS). The term “hollow anatomical structure” is a broad termand is used in its ordinary sense, including, without limitation, veins,arteries, gastric structures, coronary structures, pulmonary structures,tubular structures associated with reproductive organs such as fallopiantubes, uteri, hollow organs and the like. Hollow anatomical structuresparticularly suited to treatment or occlusion by the methods andapparatus of the disclosed embodiments include veins, such as veins ofthe lower extremities, for example, veins in the leg, and fallopiantubes.

Methods, systems, and apparatus for occluding a hollow anatomicalstructure, such as the veins shown in FIG. 1, in a patient or subjectusing an implant such as occluding device or occluding material aredisclosed. The terms “subject” and “patient” as used herein, refer toanimals, such as mammals. For example, mammals contemplated by oneskilled in the art include humans, primates, dogs, cats, sheep, cattle,goats, pigs, horses, mice, rats, rabbits, guinea pigs, and the like. Theterms “subject” and “patient” are used interchangeably.

The terms “occluding device,” “occluding implant,” and “occludingmaterial” as used herein are broad terms and are used in their ordinarysense, including, without limitation, a substance or device that iscapable of occluding or causing occlusion of a HAS. Occluding materialsor occluding devices can be formed or fabricated ex situ or formed insitu (e.g., by curing of a prepolymer or uncured polymer). The term“occluding material” as employed herein, includes prepolymers, uncuredpolymers, unsolidified materials, as well as occluding materialsinserted into a patient in polymerized, procured, or solidified form.Biologic materials, e.g., gelatin and thrombin, can also be usedseparately or in combination with the occlusive materials. Bioresorbablematerials are exemplary occluding materials, although other materialscan also be used as desired. For example, in one embodiment, theoccluding implant can include fibers and/or other components formed frompolylactides (PLA) and/or polyglycolides (PGA) or copolymers thereof.

Occluding can include, but is not limited to, blocking by insertion of aplug or other structure into the HAS, such as any one or combination ofthe veins shown in FIG. 1, that prevents or inhibits flow therethrough,adhering opposite walls of the HAS together so as to prevent or inhibitflow therethrough, compressing the walls of the HAS together so as toprevent or inhibit flow therethrough, or initiating a physiologicalreaction to an applied force or substance (e.g., energy, chemicals,drugs, physical contact, pressure or the like) that causes flow throughthe HAS to be inhibited or prevented (e.g., formation of a fibrotic plugor growth of connective tissue). Occlusion can be immediate, or onset ofocclusion can be delayed. Occlusion can be partial (i.e., permitting areduced flow through the HAS) or complete (i.e., permitting no orsubstantially no flow through the HAS). Occlusion can be permanent ortemporary. Occlusion can be affected by resorption characteristics ofthe material. Occlusion can result in physical change or damage to theHAS (e.g., tissue fibrosis or necrosis) or can block the HAS withoutsubstantial physical change (e.g., a biocompatible plug). The mechanismsby which occlusion can occur include but are not limited to formation ofan organized fibrotic occlusion resulting from the body's naturalforeign body healing response, formation of a wound or damage to tissue,expansion of the occluding device or occluding material, release of achemical or bioactive agent (e.g., a sclerosant, inflammatory agent,cytokine, growth factor, clotting factor, tissue attachment factor, orother agent) from the occluding device or occluding material,venoconstriction, compression, and ligation.

Referring to FIG. 2, an implant 10 according to one embodiment forocclusion of a hollow anatomic structure comprises a bioresorbable body12. In one embodiment, the body 12 comprises a bioresorbable material infibrous form, which can comprise a collection of individual fibers thatcan be spun into multi-filament yarns. The fibers or yarns can betextured to impart bulk. In one embodiment, multiple fibers or yarns canbe assembled together to form the body 12. The textured fibers or yarnscan be made wavy to prevent adjacent yarns from lying closely together;some fibers or yarns may tangle together. The fibers can be treatedand/or agglomerated in any suitable manner to achieve a desired texture,density, geometry, etc. The fibers can be made or treated such that thebody 12 can be compressible and/or expandable. For example, as shown inthe illustrated embodiment, the body 12 can naturally assume an expandedcondition and convert to a compressed condition upon application of acompressive force. Alternatively, the body 12 can naturally assume acompressed condition and convert to an expanded condition uponapplication of an expansive force. The bioresorbable material can be anysuitable bioresorbable material, such as a material from the family ofalpha hydroxy acids, for example polylactide (PLA) and/or polyglycolide(PGA).

Suitable forms and materials for the bulked fibrous bioresorbable body(and/or individual yarns or fibers) are disclosed in U.S. PatentApplication Publication No. 2006/0212127, published Sep. 21, 2006, andentitled, “Structures for Permanent Occlusion of a Hollow AnatomicalStructure,” and in U.S. Patent Application Publication No. 2007/0248640,published Oct. 25, 2007, and entitled, “Occlusive Implant and Methodsfor Hollow Anatomical Structure.” Of those publications, the followingis incorporated herein by reference: paragraphs 0010-0171 of PublicationNo. 2007/0248640 and the drawings referenced in those paragraphs.

In the embodiment of FIG. 2, the implant further includes a tether 14coupled to the body 12. As one example, the body 12 can be generallyelongated with a distal end 16 and a proximal end 18, the distancebetween the distal end 16 and the proximal end 18 (i.e., the length ofthe body 12) optionally being greater than the cross-sectional diameterof the body 12, and the tether 14 is coupled near or to the distal end16 of the body 12. The tether 14 can be coupled to the body 12 in anysuitable manner, examples of which include tying or stitching the tether14 to the body 12, employing a coupling agent, such as a bioresorbableor non-bioresorbable adhesive, and making the tether 14 integral withthe body 12. In the embodiment of FIG. 2, the tether 14 is coupled tothe body 12 by tying the tether 14 around the body 12 near a center ofthe length of the body 12, and the body 12 is bent or turned where thetether 14 is coupled to the body 12 such that the body 12 is folded uponitself. As a result of this configuration, the coupling location of thetether 14 forms the distal end 16 of the body 12, and the free ends ofthe body 12 folded upon each other form the proximal end 18 of the body12. The tether 14 can have any suitable length relative to the length ofthe body 12. For example, the length of the tether 14 can be greaterthan, equal to, or less than that of the body 12.

The tether 14 can be bioresorbable and made of the same material as thebody 12 or of a material different than that of the body 12.Alternatively, the tether 14 can be non-bioresorbable. Further, thetether 14 can be inelastic or elastic. In the illustrated embodiment ofFIG. 2, the tether 14 is made of the same bioresorbable material as thebody 12; the body 12 comprises multiple fibers processed and texturedsuch that the body 12 is bulked, elastic, and compressible, and thetether 14 comprises multiple fibers spun into a single, relativelysmooth, and inelastic yarn, wherein the cross-sectional diameter of thebody 12 in its natural expanded condition is significantly greater thanthe cross-sectional diameter of the tether 14.

The implant 10 can be positioned in a HAS to occlude the HAS such thatblood flow through the HAS is reduced or prevented. While the implant 10can be positioned in the HAS in any suitable manner, such as the mannersdisclosed in the above-incorporated material from a patent applicationpublication, additional or alternative techniques and/or apparatus canbe employed, as discussed herein.

In one embodiment, the implant body 12 has an overall linear massdensity of 7200 denier, and is formed from 48 plies of 75 denier, 30filament, 100% polyglycolide (PGA) yarns. The PGA material has amolecular weight (Mn) over 12,750 and a polydispersity (PDI) between 1.1and 1.8. A 30 cm length of the collected 48 plies has a breaking loadbetween 30 and 50 lbf. Among the 48 plies, 24 are “S” twisted and 24 are“Z” twisted, all with a false twist texture of 90 twists per inch. Theyarns are false twisted individually using pin twist texturing. The 48plies are doubled over once at the distal end 16 of the body 12 tocreate a 7200 denier implant body 12. The tether 14 is formed from 16plies of 75 denier, 30 filament, 100% polyglycolide (PGA) yarns. Thefilament denier is 2.5, or about 2.5. All 16 plies are “Z” twistedbetween 3 and 4 twists per inch and heat set. A 40 cm length of thecollected 16 plies has a breaking load between 10 and 17 lbf.

The 48-ply yarn is preferably cleaned by passing it in “reel to reel”fashion through an ultrasonic cleaning bath filled with ≧99% isopropylalcohol at a temperature maintained below 85 degrees Fahrenheit. Thealcohol is replaced at a rate sufficient to clean no more than 100 gramsof yarn per gallon of alcohol. After the cleaning bath the yarn is driedby running it past one or more drying air jets.

After cleaning and drying, the yarn can be further bulked by heating.From a supply reel, the yarn is passed through a roller set and thendownward in a generally vertical orientation from the roller set, andthrough a vertically oriented cylindrical heating chamber positionedbelow the roller set. A takeup reel positioned below and to the side ofthe lower end of the heating chamber takes up the yarn after it movesthrough and past the heating chamber. The roller set above the heatingchamber pulls the yarn from the supply reel and pushes it downwardthrough the heating chamber. The takeup reel is driven at a speed orspeeds that leave the yarn fairly slack between the roller set and thetakeup reel, and the yarn passes through the heating chamber in thisslack condition so that the filaments separate somewhat for heating. Theheating chamber is 4 inches long and 2 inches in inside diameter and theyarn is fed into the heating chamber at a feed speed of 0.0124 metersper second. The heating chamber heats the passing yarn with acircumferential hot air flow directed inwardly at the yarn, whichtravels approximately along the central vertical axis of the chamber.Air is flowed at a pressure of 60 PSI (+/−5 PSI) through a heateroperated at a temperature of 250-350 degrees Fahrenheit, preferably 275degrees. The heated, pressurized air then flows into the chamber via acircumferential opening or “slit” formed in the chamber inner wall. Thetemperature inside the chamber, measured at the chamber inner wall nextto the circumferential slit (and the incoming airflow) is 155-165degrees Fahrenheit. The circumferential arrangement of the hot airinflow helps to prevent asymmetric inward airflows which can tend toblow the yarn off-axis and induce tension in the yarn and therebydisrupt the bulking.

The dried and heat-bulked yarn can then be cut to the appropriate length(preferably 50 cm) and the tether 14 is tied to the midpoint. The twohalves of the yarn are folded against each other to form the implantbody 12 with the tether 14 tied at the distal end of the body 12.

The above specified parameters for the implant body 12 and tether 14 canbe varied or disregarded in other embodiments. The implant body 12 canhave a linear mass density between 6000 and 8000, or between 4000 and10,000. Between 60 and 120, or between 40 and 140, or between 20 and 200twists per inch can be employed in texturing the plies/fibers/filamentsof the implant body 12. The number and size of the plies can be varied,or a single ply can be employed. Where multiple plies are employed inthe body 12, half can be “S” twisted and half can be “Z” twisted.Bioabsorbable materials other than PGA, such as polylactic acid (PLA),or any other suitable bioabsorbable or bioresorbable material specifiedherein can be employed, either alone or in combination with other suchmaterials. For example, a mixture of PGA and PLA plies/fibers/filamentscan be used. Non-bioabsorbable or non-bioresorbable materials can beemployed as well. The filament denier in the body 12 can vary between1.5 and 3.5, or between 0.5 and 5.0, while the filament count can varybetween 2000 and 4000, or between 1000 and 5000, or otherwise to fallwithin the above specified ranges for linear mass density. Where PGA isused in forming the body 12, the molecular weight (Mn) can vary between10,000 and 15,000, or between 5,000 and 20,000.

FIG. 3 illustrates one embodiment of a system 20 with the implant 10 ofFIG. 2, or other suitable implant, and an apparatus 22 configured forstoring and/or surgically introducing the implant 10 into a HAS. Thedepicted apparatus 22 comprises a combined implant storage/introducerunit 24 adapted to store the implant 10 prior to and during introductionof the implant 10 into the HAS, and a sheath assembly 26 coupled withthe storage/introducer unit 24 adapted to facilitate introduction of animplant, such as the implant 10, into a HAS. The storage/introducer unit24 is adapted to feed the implant into the sheath assembly 26 forplacement of the implant 10 in the HAS, when manipulated by thepractitioner.

The illustrated storage/introducer unit 24 of the depicted embodimentcomprises a housing 28 sized to accommodate both the implant 10 and anintroducer assembly 30, as will be disclosed in further detail below.The assembled housing 28 comprises a coupler portion 32 for receivingthe sheath assembly 26 and coupling the implant 10 with the introducerassembly 30, an introducer portion 34 for accommodating the introducerassembly 30, and an implant storage portion 36 for accommodating theimplant 10. In the depicted embodiment, the coupler portion 32 and thestorage portion 36 are generally oriented at an obtuse angle relative toeach other, and the introducer portion 34 is located approximately atthe junction of the coupler and storage portions 34, 36 such that thestorage/introducer unit 24 has an overall “gun-like” configuration.

Referring to FIGS. 4 and 5, the housing 28 can include a right housingshell 38 and a left housing shell 40 adapted for cooperative registryand defining the coupler, introducer and storage portions 32, 34, 36. Ingeneral, the right and left housing shells 38, 40 are contoured, and canbe configured with openings, bosses, flanges, and the like, foroperational support of the elements comprising the apparatus, and can bemolded such that the openings, bosses, flanges, and the like areintegrally formed with the right and left housing shells. The right andleft housing shells 38, 40 are generally mirror images of each other,and include some, but not all, of the same structural elements.

The coupler portion 32 of the housing 28 is in communication with boththe introducer portion 34 and the storage portion 36, and is generallytubular in shape, with a generally cylindrical side wall 42 and a distalor front wall 44 including a first aperture 46 and a second aperture 48formed by cooperating openings in each of the right and left housingshells 38, 40. The first aperture 46 and the second aperture 48 can bevertically aligned, with the first aperture 46 positioned above thesecond aperture 48. A third aperture 50 is formed in the side wall 42 ator near the juncture of the coupler portion 32 with the storage portion36 by cooperating openings in each of the right and left housing shells38, 40. The coupler portion 32 further includes a cutting guide 52 and acutting block 54, both of which are provided on the inner surface of theright housing shell 38. The left housing shell 40 does not include acutting guide or cutting block. Of course, it is within the scope of thepresent disclosure for the cutting guide 52 and the cutting block 54 tobe formed on the left housing shell 40 rather than on the right housingshell 38, or for the cutting guide 52 and the cutting block 54 to beformed by cooperating features on the right and left housing shells 38,40.

The introducer portion 34 of the housing 28 is generally circular inshape, and includes a curved side wall 56 defining a portion of acircular chamber 58 in communication with the coupler portion 32 andthat is formed by the cooperative registry of a circular depression 60in the side wall of each of the right and left housing shells 38, 40. Ahollow cylindrical boss 62 is formed on the inner surface of each of theright and left housing shells 38, 40, in the approximate center of eachdepression 60. The curved side wall 56 can be continuously formed withthe side wall 42 of the coupler portion 32, and includes an elongatedslot 64 formed by cooperating openings in each of the right and lefthousing shells 38, 40.

The storage portion 36 of the housing 28 can be configured to form ahandgrip 66 for the apparatus 22 having an inner chamber 68 sized toaccommodate the implant 10 extending between a closed end 70 of thehandgrip 66 and an open end 72 of the handgrip 66 which is incommunication with the coupler portion 32. The handgrip 66 furtherincludes a distal side wall 74 and a proximal side wall 76 extend fromthe closed end 70, with the distal side wall 74 continuously formed withthe curved side wall 56 of the introducer portion 34 and the proximalside wall 76 continuously formed with the side wall 42 of the couplerportion 32.

As shown in FIG. 6, which is a cross-sectional view through theapparatus from FIG. 3 through line “VI-VI”, the implant 10 can be storedwithin the handgrip 66 in a folded manner, with the implant body 12folded upon itself one or more times. In the embodiment depicted, thehandgrip 66 has a sufficient length such that the implant body 12 isfolded once within the chamber 68 of the handgrip 66. The interior ofthe handgrip 66 further is sufficiently wide or spacious to accommodatethe folded implant 10 in its natural expanded condition. Alternatively,the interior of the handgrip 66 can be narrow or small enough tocompress the implant 10 from its expanded condition to a compressedcondition, at any appropriate degree of compression.

With further reference to FIG. 7, which is a front view of the apparatusof FIG. 3 with the housing 28 sectioned at line “VII-VII” for clarity,the introducer assembly 30 comprises a spool portion 78 around which thetether 14 of the implant 10 can be wound and a reel mechanism 80 coupledto the spool portion 78 for retrieval of the tether 14 from the sheathassembly 26 and to wind the tether 14 onto the spool portion 78, as willbe described in greater detail below.

The spool portion 78 includes an axle 84 extending between the bosses 62formed on the right and left housing shells 38, 40 and a generally flat,circular spool 86 mounted to the axle 84 and received within the chamber58 of the introducer portion 34 of the housing 28. The axle 84 can berotatably mounted to the housing shells 38, 40, such that the ends ofthe axle 84 may rotate within the hollow bosses 62.

The spool 86 includes a barrel 88 between two end flanges 90, with acentral bore 92 extending through the barrel 88 and flanges 90. The endflanges 90 have a larger diameter than the barrel 88 to retain thetether 14 when wound around the barrel 88. The bore 92 can receive theaxle 84 by a friction fit to fixedly mount the spool 86 to the axle 84;thus, the spool 86 rotates with the axle 84. In another contemplatedembodiment, the axle 84 may be fixed with respect to the housing 28, andthe spool 86 may rotated relative to the stationary axle 84.

The spool 86 can be offset within the housing 28, such that the spool 86is primarily received within the depression 60 in the right housingshell 38. The spool 86 can further serve as an anchor for the free endof the tether 14 (e.g. the end of the tether 14 not coupled to the body12 of the implant 10, as shown in FIG. 2) stored within the apparatus22. For example, anchoring the free end of the tether 14 to the barrel88 of the spool 86 ensures that the tether 14 will be wound onto thebarrel 88 automatically when the reel mechanism 80 is actuated, as willbe described in greater detail below.

The reel mechanism 80 comprises a one-way clutch assembly 94 and anactuator 96 coupled to the clutch assembly 94. The clutch assembly 94permits the transmission of rotation to the spool 86 in only onedirection, and further locks the position of the spool 86 and preventsreverse rotation when the input force from the actuator 96 is removed.In one embodiment, the clutch assembly 94 comprises a one-way needlebearing 98 around the axle 84 that is coupled to the actuator 96 suchthat movement of the actuator 96 is translated to rotational movement ofthe needle bearing 98, as will be described in more detail below. Onesuitable needle bearing 98 is model no. RC02 available from The TimkenCo., or part no. 2489K22 available from McMaster-Carr Supply Co.

The depicted actuator 96 comprises a control lever 100 having a gripportion 102 and a ring portion 104 coupled to the grip portion 102 by aneck portion 106. The control lever 100 is received by the introducerportion 34 of the housing 28, with the ring portion 104 received aroundthe axle 84 and the neck portion 106 extending through the slot 64 suchthat the grip portion 102 is exterior of the housing 28. The slot 64 maybe elongated or otherwise sized to accommodate the range of movement ofthe control lever 100 with respect to the housing 28.

The ring portion 104 receives the needle bearing 98 to couple thecontrol lever 100 to the axle 84, such that rotation of the ring portion104 causes one-way rotation of the axle 84, thereby causing one-wayrotation of the spool 86. The ring portion 104 therefore translates thepivotal movement of the grip portion 102 to rotational movement of theaxle 34.

As shown in FIG. 7, the neck portion 106 can be slightly tapered tooffset the ring portion 104 from the grip portion 102. The offset ringportion 104 allows space for the spool 85 within the housing 29 whilepermitting the grip portion 102 to remain relatively centered withrespect to the handgrip 66.

The handgrip 66 of the storage portion 36 and the control lever 100 ofthe introducer portion can be cooperatively shaped to facilitatecomfortable gripping of the storage/introducer unit 24 with a singlehand of a practitioner. As illustrated, the grip portion 102 includesgrip features 108 to facilitate handling of the apparatus 22 by apractitioner. Particularly, the grip features 108 may be ergonomicallyshaped or otherwise formed to facilitate gripping the control lever 100with one or more fingers of a single hand of the practitioner. Thehandgrip 66 can further be ergonomically shaped or otherwise formed tofacilitate gripping the handgrip 66 with the palm and thumb of the samesingle hand of the practitioner. The apparatus 22 can be grippedaccording to the practitioner's preference, such as with a single handwrapped around the handgrip 66 and the control lever 100, with some orall of the fingers of the single hand engaged with the grip features 108on the control lever 100 and the palm and thumb of the same single handengaged with the handgrip 66, although other gripping arrangements ortechniques are possible. Further, the handgrip 66 and the control lever100 can be shaped to facilitate an equally comfortable gripping of theapparatus 22 by a left-handed practitioner or a right-handedpractitioner.

Depression of the control lever 100, i.e. squeezing the control lever100 toward the handgrip 66 of the housing 28, causes the spool 86 torotate in a counterclockwise direction, per the orientation shown inFIG. 6, by way of the needle bearing 98 between the control lever 100and the axle 84. Rotation of the spool 86 draws a length of the tether14 onto the barrel 88, which advances the implant 10 distally throughthe apparatus 22, as will be described in further detail below. In someembodiments, an electric motor (not shown) can be employed to rotate thespool 86, in place of the control lever 100, etc.; in such embodimentsthe motor can be powered by an onboard battery and actuated by a triggerswitch or the like located on or near the handgrip 66.

While not illustrated herein, the storage/introducer unit 24 can beprovided with a safety feature to prevent unwanted or inadvertentactuation of the introducer assembly 30 to avoid accidental advancementof the implant 10. For example, the actuator 96 can be provided with asafety lock that must be removed or unlocked before the control lever100 can be depressed.

Referring to FIG. 8, which is a close-up view of a portion of FIG. 6with the inner and outer sheaths 148, 146 and implant 12 not shown forclarity, the coupler portion 32 houses a tether cutting assembly 112 anda sheath cutting assembly 114. The tether cutting assembly 112 includesthe cutting guide 52 and cutting block 54 formed on the right housingshell 38, as well as a moveable cutting actuator 116 which is guided bythe cutting guide 52 and which engages the cutting block 54 to sever thetether 14 of the implant 10, as will be described in greater detailbelow.

The cutting guide 52 includes an upper wall 118 and an angled rear wall120. The upper wall 118 is joined at one end to the front wall 44 of thecoupler portion 32 and at the opposite end to the angled rear wall 120,which is in turn joined to the side wall 42; the walls of the cuttingguide 118, 120 and the coupler portion 32 thereby form a substantiallyenclosed guide channel 122. The guide channel 122 extends between anaperture 124 formed in the angled rear wall 120 and the lower secondaperture 48 in the front wall 44 of the coupler portion 32. The aperture124 in the angled rear wall 120 is generally aligned with and incommunication with the lower aperture 48 in the front wall 44.

The cutting block 54 includes a cutting surface 126 in opposed relationto the aperture 124 of the cutting guide 52. In the depicted embodiment,the cutting surface 126 is generally parallel to and spaced from therear wall 120 of the cutting guide 52. The space between the cuttingsurface 126 and the rear wall 120 defines a channel 128 in communicationwith the introducer portion 34 of the housing 28.

The cutting actuator 116 has an elongated shaft 130 with a triggerbutton 132 at the distal end of the shaft 130 and a cutting element 134at the proximal end of the shaft 130. As depicted, the cutting element134 can be formed as an angled cutting edge 136 on the terminal end ofthe shaft 130. The shaft 130 can be received within the channel guide122, with a portion of the shaft 130 projecting through the lower secondaperture 48 on the front wall 44, such that the trigger button 132 is onthe exterior of the housing 28, and the cutting element 134 is alignedwith the aperture 124. In one embodiment, the cutting actuator 116 isbiased to a position in which the cutting element 134 is spaced from thecutting surface 126 by a biasing element (not shown).

While not illustrated herein, the apparatus 22 can be provided with asafety feature to prevent unwanted or inadvertent actuation of thetether cutting assembly 112 to avoid accidentally cutting the tether 14.For example, tether cutting assembly 112 can be provided with a safetylock that must be removed or unlocked before the cutting actuator 116can be depressed.

The sheath cutting assembly 114 includes a blade holder 142 extendingfrom the upper wall 118 of the cutting guide 52 and having athrough-opening 143 formed therein. A blade 144 is supported by theblade holder 142 below the through-opening 143. The blade 144 mayinclude a wedge-shaped tip 145. In one embodiment, the tip 145 may besharpened or otherwise formed as a cutting tip.

Referring to FIG. 9, the illustrated sheath assembly 26 includes anouter sheath 146 and an inner sheath 148. As least a portion of theinner sheath 148 can be received by the outer sheath 146. The outersheath 146 has a tubular and flexible shaft 150 defining a lumen 152,and having an open distal end 154 and an open proximal end 156. Anaperture 158 may be formed in the sidewall of the shaft 150, between thedistal and proximal ends 154, 156; as illustrated, the aperture 158 canbe formed closer to the proximal end 156 than the distal end 158. Theouter sheath 146 can be formed from materials suitable for use in theconstruction of standard introducer sheaths, including Pebax, HDPE, FEP,PTFE, or nylon. The outer sheath 146 can be sized for insertion into aHAS; as an example, the outer sheath 146 can be 8 French with an outerdiameter of about 3.38 mm and inner diameter of about 2.79 mm, and alength of about 55 cm measured from the distal end of thestorage/introducer unit 24. The outer sheath 146 can further be sizedfor receipt of the body 12 of the implant 10.

The inner sheath 148 has a tubular and flexible shaft 160 defining alumen 162. The inner sheath 148 can be sized for receipt within thelumen 152 of the outer sheath 146; as an example, the shaft 160 of theinner sheath 148 can have an outer diameter of about 1.10 mm and aninner diameter of about 0.72 mm. The inner sheath 148 can further besized for receipt of the tether 14 of the implant 10. The inner sheath148 can comprise a metallic (e.g. stainless steel such as type 304stainless steel) tube or hypotube with the distal end thereof formedinto the pulley feature 172. However, any suitable member can beemployed as the inner sheath 148 that has sufficient column strength tohold the pulley feature 172 in position against the tension in thetether 14 as the implant body 12 is drawn distally. For example, a solid(lumen-less) rod with the pulley feature 172 or similar structure at thedistal end thereof can be employed in place of the inner sheath 148;where such a rod is employed, the portion of the tether 14 that wouldotherwise reside in the inner sheath lumen can extend alongside the rodwithin the outer sheath lumen.

As shown, the shaft 160 of the inner sheath 148 terminates in a proximalend region 164 and a distal tip region 166. The proximal end region 164extends through the aperture 158 of the outer sheath 146 and includes anopen proximal end 168 of the shaft 160. The proximal end region 164curves and/or angles away from the longitudinal axis of the shaft 160 inorder to pass through the aperture 158 in the side wall of the shaft 150of the outer sheath 146. As illustrated, the distal tip region 166 canbe flush with or proximally of the open distal end 154 of the shaft 150.Alternatively the distal tip region 166 can project distally of theouter sheath 146 by a short distance.

With additional reference to FIG. 10, which is an enlarged perspectiveview of the distal tip region 166 of the inner sheath 148 (with thetether 14 and the outer sheath 146 not shown for clarity), the distaltip region 166 includes a distal opening 170 providing access to thelumen 162 and a bearing surface or pulley feature 172 which changes orreverses the direction of the force applied by the introducer assembly30 on the implant body 12 via the tether 14, as will be described ingreater detail below. The distal opening 170 can be formed at the distalterminal end of the shaft 160. The pulley feature 172 defines a pulleylumen 174 having a distal opening which forms an inlet opening 176 tothe pulley lumen 174 and a proximal opening which forms an outletopening 178 from the pulley lumen 174. The pulley lumen 174 is incommunication with the lumen 162 of the inner sheath 148 via the inletopening 176. In the depicted embodiment, the pulley feature 172 isformed by a semi-circular arched wall 180 that is open at its outerside, thus providing an open pulley lumen 174; however, the pulleyfeature 172 can alternately be closed to form an enclosed pulley lumen.The opening at the outer side of the wall 180 is generally continuouswith the distal opening 170 of the shaft 160. The arched wall 180 canhave a semi-circular shape to help retain the tether 14 within thepulley lumen 174 when tension is applied to the tether 14. Instead ofthe depicted pulley 172, a rounded (e.g. cylindrical or hemicylindrical)bar or tube can be disposed at the distal end of the inner sheath 148and oriented orthogonal to the longitudinal axis of the inner sheath148, such that a curved distal surface of the bar or tube faces distallyand away from the inner sheath 148. Such a curved distal surface can actas a bearing surface or pulley surface over which the direction oftravel of, and tension in, the tether 14 is changed or reversed. Agroove or V-shaped channel can be formed in such a bearing/pulleysurface to prevent the tether 14 from slipping off the surface duringuse. In its various forms, the bearing surface or pulley feature 172 canbe located at or near the distal end of the outer sheath 146, within thelumen 162 of the outer sheath 148 as depicted, or partially orcompletely distal of the outer sheath 148, in which case the bearingsurface or pulley feature 172 can be aligned with the lumen 162 (e.g.not protruding radially outward beyond a distal projection of the lumen162).

As shown in FIG. 9, the tether 14 extends through both the outer sheath146 and the inner sheath 148 for cooperative movement during advancementof the sheath assembly 26. In the illustrated embodiment, the tether 14extends from the spool 86 (FIGS. 6, 11) and enters the lumen 162 of theinner sheath 148 through the open proximal end 168 of the shaft 160. Thetether 14 extends through lumen 162 and passes into the pulley lumen 174of the pulley feature 172 through the inlet opening 176. The tether 14then reverses direction over the pulley feature 172 and passes out ofthe pulley lumen 174, through the outlet opening 178 and into the lumen152 of the shaft 150 of the outer sheath 146, and thereafter passes outof the outer sheath 146 via the open proximal end 156 of the shaft 150.

Referring to FIG. 11, which is a close-up cross-sectional view throughthe apparatus 22 from FIG. 3, a handle 182 for the outer sheath can beprovided as illustrated. The handle 182 includes a hub 184 attached to aproximal end of the shaft 150 of the outer sheath 146 and a circulargrip 186 projecting from a proximal portion of the hub 184, generally atan angle with respect to the longitudinal axis of the outer sheath 146.The circular grip 186 can be formed with or attached to the hub 184.

The hub 184 comprises an opening 188 which receives the shaft 150 tomount the outer sheath 146 to the handle 182, and a side port 190extending from the opening 188. The side port 190 is in communicationwith the lumen 152 of the outer sheath 146 via the open proximal end156. The side port 190 can be tapered such that the cross-sectional areaof the side port 190 decreases in a direction toward the shaft 150. Thistapering facilitates the compression of the implant 10 as it enters theouter sheath 146 through the side port 190, as will be described in moredetail below.

The handle 182 is received by the coupler portion 32 of the housing 28,with the hub 184 projecting through the third aperture 50 formed at ornear the juncture of the coupler portion 32 with the storage portion 36of the handle 28 such that the circular grip 186 is exterior of thehousing 28. The outer sheath 146 projects distally from the opening 188in the hub 184 and passes through the upper first aperture 46 in thefront wall 44 of the coupler portion 32. In this position, the outersheath 146 is aligned with the sheath cutting assembly 114.Particularly, the shaft 150 of the outer sheath 146 is adjacent toand/or engaged with the blade 144 of the sheath cutting assembly 114,such that the tip 145 will cut the sidewall of the shaft 150 as theouter sheath 146 is withdrawn from the housing 28, as will be describedin greater detail below. In an alternate embodiment, the shaft 150 ofthe outer sheath 146 can be precut, and the blade 144 of the sheathcutting assembly 114 may function to simply part the precut shaft 150 toclear the inner sheath 148 as the outer sheath 146 is withdrawn from thehousing 28 rather than create a new cut in the shaft 150.

The inner sheath 148 extends through the outer sheath 146, with theproximal end region 164 extending through the aperture 158 of the outersheath 146 and into the channel 128 between the cutting guide 52 and thecutting block 54 such that the open proximal end 168 of the shaft 160 ofthe inner sheath 148 is in communication with the channel 128. The shaft160 of the inner sheath 148 further passes through the through-opening143 formed in the blade holder 142 of the sheath cutting assembly 114,which helps to maintain the position of the inner sheath 148 withrespect to the housing 28 as the outer sheath 146 is withdrawn from thehousing 28, as will be described in greater detail below.

The tether 14 of the implant 10 extends from the spool 86 and passesthrough the channel 128 between the cutting guide 52 and the cuttingblock 54 to enter the open proximal end 168 of the shaft 160 of theinner sheath 148. The tether 14 then follows the path through theintroducer assembly 26 shown in and described with respect to FIGS. 9and 10. The portion of the tether 14 that passes out of the openproximal end 156 of the shaft 150 of the outer sheath 146 exits the hub184 through the side port 190, and joins the implant body 12 storedwithin the chamber 68 of the handgrip 66, as shown in and described withrespect to FIG. 6.

While not illustrated, the apparatus 22 can further be provided with asafety feature to prevent unwanted or inadvertent withdrawal of theouter sheath 146 from the housing 28. For example, the handle 182 can beprovided with a safety lock that must be removed or unlocked before thehandle 182 can be moved relative to the housing 28.

During the storage and introduction of the implant 10, the implant body12 assumes multiple conditions with respect to the expansion andcompression of the implant body 12. FIGS. 12-15 illustrate sectionalviews of the implant body 12 in the exemplary conditions. As examples,the implant body 12 in the illustrated embodiment assumes an unstressedor “natural” expanded condition when in the handgrip 66 of the storageportion 36 of the apparatus 22 during storage (e.g., a storagecondition, FIG. 12), a first compressed condition when in the outersheath 146 of the sheath assembly 26 during introduction (e.g., a firstintroduction condition, FIG. 13), a second compressed condition when inthe outer sheath 146 adjacent the inner sheath 148 of the sheathassembly 26 during introduction (e.g., a second introduction condition,FIG. 14), and, assuming the HAS has a differing cross-sectional diameterthan the outer sheath 146 with or without the inner sheath 148, a thirdcompressed condition when in the HAS, shown as the greater saphenousvein B for illustrative purposes, after implantation (e.g., animplantation condition, FIG. 15). The implant body 12 also undergoestransitional conditions when converting between the storage, firstintroduction, second introduction, and implantation conditions. Theseconditions can be imposed on the implant body 12 because of thecross-sectional diameter of the structure that houses the implant body12; once the housing structure cross-sectional diameter is sufficient tocause compression of the implant body 12, compression of the implantbody 12 increases as the housing structure cross-sectional diameterdecreases. The housing structures corresponding to the storage, firstintroduction, second introduction, and implantation conditions of theillustrated embodiment are, respectively, the handgrip 66 of the implantstorage portion 36, the shaft 150 of the outer sheath 146 without andwith the inner sheath 148 extending through the lumen 152 of the shaft150, and the HAS, in this case, the greater saphenous vein B.

Embodiments of methods of use of the system 20 are described below.While the system 20 can be employed in conjunction with any suitableHAS, the methods are described with respect to the greater saphenousvein B for illustrative purposes. It will be understood that the methodscan be modified or adapted as necessary, if necessary, for use in otherHASs. The methods can also be modified or adapted as necessary, ifnecessary, for use with embodiments of the system 20 other than theembodiment employed in the following description. In the description ofthe methods, various steps are discussed in terms of being performed bythe practitioner using a single hand; however, it is understood thatthese steps may be performed by the practitioner using both hands or byalternating hands. It is assumed that prior to the embodiment of themethod of use of the system 20 described below, that the implant 10 isstored within the apparatus 22 as described and shown in the precedingfigures; including the implant body 12 of the implant 10 stored withinthe handgrip 66 and the tether 14 of the implant 10 passing from thehandgrip 66, though the sheath assembly 26 and to the spool 86 of theintroducer assembly 30. The tether 14 of the implant 10 is therebycoupled between the implant body 12 and the spool 86.

In one embodiment of a method of use of the system 20, various stages ofwhich are depicted in FIGS. 16-29, the target HAS (e.g., a vein such asthe greater saphenous vein B) can first be accessed at an access sitethrough the skin by using a suitable access technique (e.g., theSeldinger technique). In one example, the vein B is punctured with ahollow access needle, optionally under ultrasonic guidance, and aguidewire is passed into the vein B through a lumen of the needle. Theneedle is then withdrawn, and the sheath assembly 26 is fed over theguidewire into the vein B and advanced to the desired implant location.In the case of the greater saphenous vein B, the desired implantlocation is just below the sapheno-femoral junction H. The guidewire isthen withdrawn from the sheath assembly 26, thereby leaving the sheathassembly 26 or a portion thereof in the vein B. The position of thesheath assembly 26 relative to the vein B and the sapheno-femoraljunction H can be verified using appropriate techniques, such asultrasound imaging. Optionally, a dilator can be employed with thesystem 20 to feed the sheath assembly 26 over the guidewire. The dilatoris inserted into the lumen 152 of the shaft 150 through the open distalend 154 in the space between the sidewall of the shaft 150 and the innersheath 148. In one embodiment, the dilator can include a flattened sideto account for the inner sheath 148 within the outer sheath 146.

FIG. 16 illustrates the leg A with the sheath assembly 26 located in thegreater saphenous vein B and the storage/introducer unit 24 positionedexternally of the leg A. FIG. 17 provides an enlarged view of the regionlabeled “XVII” in FIG. 16 to show the location of the distal portion ofthe sheath assembly 26, including the distal tip region 166 of the innersheath 148, in the saphenous vein B and relative to the sapheno-femoraljunction H.

When the apparatus 22 is oriented as desired, the practitioner canoptionally remove a safety feature (not shown) preventing unwanted orinadvertent actuation of the introducer assembly 30; the apparatus 22 inthis state is ready for introduction of the implant 10 into the vein B.The practitioner grasps the handgrip 66 and the control lever 100 andbegins to reel in the tether 14 by applying a proximal force to thecontrol lever 100 to effectively squeeze the control lever 100 towardthe handgrip 66 of the housing 28, as illustrated by the arrow X in FIG.18, thereby advancing the implant 10 out of the implant storage portion36 and through the coupler assembly 32. In particular, depressing thecontrol lever 100 causes the spool 86 to rotate by way of the needlebearing 98 between the control lever 100 and the axle 84. Rotation ofthe spool 86 draws a length of the tether 14 onto the barrel 88. Thisshortens the effective length of the tether 14, which can be defined asthe unwound length of the tether 14 between the spool 86 and the distalend 16 of the implant body 12.

With reference to FIG. 19, the shortening of the effective length of thetether 14 pulls the implant body 12 distally through the outer sheath146 by virtue of the pulley feature 172, which changes the direction ofthe force applied by the introducer assembly 30 on the implant body 12via the tether 14. Specifically, the pulley feature 172 changes theforce of the tether 14 from a proximally-directed force F1 within theinner sheath 148 to a distally-directed force F2 within the outer sheath146.

As depicted in FIG. 20, the force of the tether 14 on the implant body12 pulls the implant body 12 distally through the side port 190 in thehub 184 of the handle 182 to enter the open proximal end 156 of theshaft 150 of the outer sheath 146. After entering the open proximal end156, the implant 10 continues its advancement through the lumen 152 ofthe outer sheath 146.

As the tether 14 pulls the implant 10 further distally into the outersheath 146, the body 12 of the implant 10 converts from its expandedcondition, an example of which is shown in FIG. 12, to the firstcompressed condition, shown in FIG. 13, as a result of the relativelysmall cross-sectional diameter of the side port 190 and the lumen 152;further, the taper of the side port 190 effectively forces the implantbody 12 to compress in order to pass therethrough. Lengthening of theimplant body 12 can accompany the compression.

Referring to FIG. 21, as the tether 14 pulls the implant 10 further intothe outer sheath 146, the implant 10 converts from the first compressedcondition, shown in FIG. 13, to the second compressed condition, shownin FIG. 14, as a result of the entry of the inner sheath 148 into thelumen 152 of the outer sheath 146 at the aperture 158, which reduces thecross-sectional diameter of lumen 152 available for the implant 10 topass through. The curvature of the inner sheath 148 at the proximal endregion 164 facilitates the compression of the implant body 12 as itapproaches the inner sheath 148 by gradually reducing the size of thespace between the outer sheath 146 and the inner sheath 148. Further, aportion of the implant body 12 may temporarily expand to project out ofthe aperture 158 of the outer sheath 146 as that portion of the implantbody 12 passes by the aperture 158, but is also gradually compressed asit encounters the proximal end region 164 of the inner sheath. Thelength of the implant body 12 can be selected so that the proximal endof the (compressed) implant body 12 is located just distal of the sideport 190 or the hub 184 when the distal end of the implant body 12 hasbeen advanced to the distal end of the inner sheath 148. As a result,there will be no excess implant material to interfere with theretraction and removal of the outer sheath 146.

The tether 14 and the implant 10 cease advancement when reaching thedesired implant location, which is just below the sapheno-femoraljunction H in the present example. The control lever 100 can be actuateda sufficient number of cycles, wherein each depression and release ofthe control lever 100 defines one cycle, to draw the implant to thedesired implant location. FIG. 19 illustrates the implant 10 fullyadvanced into the greater saphenous vein B to just below thesapheno-femoral junction H. In one embodiment, the practitioner advancesthe implant 10 until the distal end 16 of the implant body 12 is near oradjacent to the open distal end 154 of the shaft 150 of the outer sheath146 as observed under imaging guidance, such as ultrasound guidance.Depending on the resolution of the imaging equipment and other factors,the distal end 16 of the implant body 12 can be flush with the opendistal end 154 of the shaft 150 (i.e., the implant body 12 end does notproject beyond the shaft 150), or the distal end 16 of the implant body12 can project beyond the open distal end 154 of the shaft 150 whenobserved as being aligned. In another embodiment, the practitioner canadvance the distal end 16 of the implant body 12 beyond the open distalend 154 of the shaft 150. In one embodiment, with the implant 10 fullyadvanced, the implant body 12 extends along the entire length of thelumen 152 of the shaft 150.

While the method of use of the system 20 is described in terms ofadvancement of the sheath assembly 26 and the implant 10 to place theimplant 10 at the desired implant location, some proximal retraction ofthe sheath assembly 26 may also accompany the placement of the implant10. Since the outer sheath 146 covers the inner sheath 148 and implant10, the sheath assembly 26 can be retracted proximally to withdraw theinner sheath 148 and the implant 10, which is a useful feature in casethe inner sheath 148 and the implant 10 are advanced beyond the desiredimplant location.

After the implant 10 is advanced to the desired implant location, thepractitioner disconnects the outer sheath 146 from the housing 28 bygripping the handle 182 and pulling the outer sheath 146 proximallythrough the third aperture 50 and out of the housing 28, as illustratedin FIG. 22. This step may be preceded by the optional removal of asafety feature (not shown) preventing unwanted or inadvertent withdrawalof the outer sheath 146 from the housing 28.

Referring to FIG. 23, which is a schematic underside view of the sheathcutting assembly 114, as the outer sheath 146 is pulled proximally, theblade 144 of the sheath cutting assembly 114 creates a cut 192 in thesidewall of the shaft 150 and the blade holder 142 parts the sidewall ofthe shaft 150 around the inner sheath 148, such that the outer sheath146 can be removed without disturbing the position of the inner sheath148. Furthermore, the inner sheath 148 is fixed to the blade holder 142in the opening 143 thereof, thereby maintaining the position of theinner sheath 148 with respect to the housing 28 as the outer sheath 146is withdrawn from the housing 28. In other words, the blade holder 142securely holds, and prevents any substantial proximal movement of, theinner sheath 148 as the shaft 150 of the outer sheath 146 is retractedproximally over the inner sheath 148 (and implant 10, where present). Asdiscussed above, in an alternate embodiment, the shaft 150 of the outersheath 146 can be precut; in this case, the blade 144 of the sheathcutting assembly 114 may be a simple post or unsharpened wedge whosefunction is to simply initiate the parting of the precut shaft 150 toclear the inner sheath 148 as the outer sheath 146 is withdrawn from thehousing 28 rather than create a new cut in the shaft 150.

During the retraction and decoupling of the outer sheath 146, the innersheath 148 and the implant 10 remain in the position shown in FIG. 24 inthe vein B; thus, the outer sheath 146 moves proximally along and overthe inner sheath 148, thereby exposing the inner sheath 148 and implantbody 12. As the outer sheath 146 is retracted, it is withdrawn from thevein B, and the implant body 12 expands from the compressed conditionwhen in the shaft 150 to effectively fill the vein B less the spaceoccupied by the inner sheath 148. FIG. 25 illustrates the inner sheath148 and the implant 10 in the greater saphenous vein B after completeremoval of the outer sheath 146 from the vein B.

At this point, some proximal retraction of the inner sheath 148 can alsoaccompany the placement of the implant 10. Since the inner sheath 148and implant 10 are coupled by the tether 14, the inner sheath 148 can beretracted proximally to withdraw the distal portion of the implant 10somewhat within the HAS, which is a useful step that can add additionalbulk to distal portion of the implant 10 after it has been placed at thedesired implant location.

Also after the implant 10 has been advanced to the desired implantlocation, the practitioner cuts the tether 14 using the tether cuttingassembly 112. This step may be preceded by the optional removal of asafety feature (not shown) preventing unwanted or inadvertent actuationof the tether cutting assembly 112. In the illustrated embodiment, thetether 14 is cut after the outer sheath 146 has been removed.

Referring to FIG. 26, to cut the tether 14, the practitioner appliesproximal force to the trigger button 132 to move the cutting actuator116 proximally within the guide channel 122. Continued application ofproximal force causes the cutting element 134 project through theaperture 124 to engage the tether 14 in the channel 128 between thecutting guide 52 and the cutting block 54 and force the tether 14against the cutting block 54. Specifically, the cutting edge 136 of thecutting element 134 presses the tether 14 against the cutting surface126 of the cutting block 54, thereby severing the tether 14. Thereafter,a portion of the tether 14 remains coupled to the implant body 12, whilethe other portion of the tether 14 remains wound on the spool 86.

After cutting the tether 14 of the implant 10, the practitioner pullsapparatus 22 and, thus, the inner sheath 148, proximally away from theleg A to completely withdraw the inner sheath 148 from the vein B. Sincethe tether 14 has been cut, the tether 14 easily slides out of the innersheath 148 as the inner sheath 148 is withdrawn. If desired, thepractitioner can apply external compression to the vein B and theimplant 10 to maintain the position of the implant 10 in the vein B. Thedistal end 16 of the implant 10 retains its position in the vein Bduring retraction of the inner sheath 148 due to its apposition againstthe vein wall, which can be aided with coagulation or “sticking” by anyblood that is present in the vicinity. As the inner sheath 148 iswithdrawn from the vein B, the implant body 12 expands to effectivelyfill the vein B. FIG. 27 illustrates the implant 10 in the greatersaphenous vein B after removal of the inner sheath 148. FIG. 15illustrates a cross-section of the greater saphenous vein B afterimplantation of the implant 10.

Upon removal of the inner sheath 148 and the storage/introducer unit 24,the implant 10 is situated in the vein B as shown in FIGS. 27 and 28,with the implant body 12 and tether 14 extending along the vein lumenfrom the distal tip of the implant 10 (in this case, near the junctionH) toward the access site in the vein B. The tether 14 (and, if desiredthe implant body 12 as well) extend through the vein wall at the accesssite, and into the tissue tract formed during vein access and located inthe subcutaneous tissue between the vein wall and the skin surface. Thetether 14 (and, if desired, the implant body 12) pass through the tissuetract and emerge from the leg A at the skin surface. FIG. 29 shows thetether 14 emerging from the skin surface in this manner.

The practitioner can optionally secure the implant 10 to the leg Afollowing removal of the inner sheath. In one embodiment, the tether 14can be trimmed a desired length beyond the location where the tether 14exits the leg A to form a tether securing portion 194 projecting fromthe leg A. If the implant body 12 protrudes from the leg, the implantbody 12 can also be trimmed at the location where the implant body 12exits the leg A (i.e., the access site); however, because the apparatus22 can employ a shorter implant 10 as discussed above, the implant body12 may not protrude from the leg A once it is implanted, and trimmingthe implant body 12 may be unnecessary. The securing portion 194 can betaped or otherwise attached to the exterior surface, i.e., the skin, ofthe leg A, as shown in FIG. 28 and in greater detail in FIG. 29, whichis an enlarged view of the exterior surface of the leg A, particularlythe region of the leg A labeled “XXIX” in FIG. 28. With the distal endof the tether 14 attached to the distal end 16 of the implant body 12,and with the securing portion 194 attached to the skin, the tether 14prevents migration of the implant 10 in the direction of thesapheno-femoral junction. In another embodiment, the implant 10,including the tether 14, can be secured to the access site byincorporation with access site sutures, such as 4-0 Vicryl braided orsimilar sutures. Where the implant body 12 extends into or through theaccess tissue tract as discussed above, the proximal end portion of thebody 12 can be tucked into the tract within the subcutaneous tissue toenhance anchoring of the implant 10, or it can be secured to the skinsurface as shown with the tether 14 in FIG. 29.

The order of the steps described above for the method of use of thesystem 20 can be performed in any desired and suitable order and are notintended to be limited to the order the steps are described above.

The method can be used with the illustrated apparatus 22, otherembodiments of the illustrated apparatus 22, or other types of apparatusfor storage and/or introduction of the implant 10 or other suitableimplant. Similarly, the apparatus 22 can be employed with theillustrated implant 10, other embodiments of the illustrated implant 10,or other types of occluding implants. The case is the same with respectto the use of the sheath assembly 26 with the apparatus 22 and withrespect to the use of the inner sheath 148 with the sheath assembly 26.

The apparatus 22 herein disclosed can be easily handled and manipulatedby the practitioner using a single hand due to various aspects of theapparatus 22. One exemplary contributing aspect is the “gun-like”configuration of the storage/introducer unit 24, which permits thepractitioner to hold the storage/introducer unit 24 and actuate theintroducer assembly 30 to introducer the implant 10 into a HAS using asingle hand. This leaves the practitioner's other hand free, whichallows the practitioner to perform other actions during implantintroduction, such as operating an imaging device, for example anultrasonic device, to view the target HAS and the desired implantlocation.

The apparatus 22 can be provided as a ready-to-use kit having theimplant 10 disposed in the implant storage portion 36 of the housing 28and the tether 14 connected to the spool 86 and threaded through thesheath assembly 26 such that the apparatus 22 (e.g., as shown in FIGS.3, 6, 9 and 11) can be removed from its packaging for immediate surgicaluse. In one embodiment, the apparatus 22 can be a single use device thatis disposed after surgical use. Alternatively, the apparatus can be amultiple use device that can be sterilized and provided with a newimplant 10 and, if necessary, a new outer sheath 146, for each surgicaluse.

The above description presents the best mode contemplated for carryingout the present apparatus and methods for storage and/or introduction ofimplant for hollow anatomical structure, and of the manner and processof practicing them, in such full, clear, concise, and exact terms as toenable any person skilled in the art to which they pertain to practicethese apparatus and methods. These apparatus and methods are, however,susceptible to modifications and alternate constructions from thosediscussed above that are fully equivalent. Consequently, these apparatusand methods are not limited to the particular embodiments disclosed. Onthe contrary, these apparatus and methods cover all modifications andalternate constructions coming within the spirit and scope of theseapparatus and methods as generally expressed by the following claims,which particularly point out and distinctly claim the subject matter ofthese apparatus and methods.

What is claimed is:
 1. Apparatus for delivering an implant, theapparatus comprising: a housing; a sheath portion extending distallyaway from the housing, the sheath portion having a sheath with a sheathlumen; wherein the implant comprises an implant body and a tetherconnected to the implant body, and the implant has a first position inwhich the implant body is at least partially located within the housing,and the tether extends distally along and within the sheath portion, andturns to extend back proximally along and within the sheath portion;wherein the apparatus further comprises a reel that is configured towind the tether and thereby draw the implant body distally along andwithin the sheath lumen to a second position; wherein the sheath portionfurther comprises an inner member extending along and within the sheathlumen, the inner member providing a bearing surface at or near thedistal end of the sheath, within or aligned with the sheath lumen; andwherein the tether has a first portion that extends from the implantbody distally within the sheath portion and around the bearing surface,where the tether changes direction, and extends back proximally, as asecond portion, from the bearing surface along and within the sheathportion.
 2. The apparatus of claim 1, wherein the sheath portion issized and configured for percutaneous insertion into a blood vessel. 3.The apparatus of claim 1, wherein the implant body is self-expanding,and the implant body is in an expanded configuration when the implant isin the first position.
 4. The apparatus of claim 3, wherein the implantbody is stored within the housing when the implant is in the firstposition, and no portion of the implant body is in the sheath lumen. 5.The apparatus of claim 1, wherein the inner member comprises an innermember lumen extending within the inner member, and the first tetherportion extends along and within the inner member lumen, proximallytoward the reel.
 6. The apparatus of claim 1, wherein the sheath isretractable proximally to expose the inner member.
 7. The apparatus ofclaim 6, further comprising a sheath parting member that projects intothe sheath lumen through an opening in a sidewall of the sheath, whereinthe sheath parting member is configured to part the sidewall of thesheath as the sheath is retracted proximally.
 8. The apparatus of claim7, wherein the sheath parting member comprises a sharpened blade thatcuts through the sheath sidewall as the sheath is retracted.
 9. Theapparatus of claim 7, wherein the sheath sidewall has a score line andthe sheath parting member comprises a post or unsharpened wedge thatsplits the sheath sidewall along the score line as the sheath isretracted.
 10. The apparatus of claim 7, wherein: the inner membercomprises an inner member lumen extending within the inner member, andthe first tether portion extends along and within the inner memberlumen; and a proximal portion of the inner member comprises a lateralprojection that turns and extends radially outward to pass out of thesheath lumen, at a location proximal of the sheath parting member; suchthat the lateral projection of the inner member is positioned betweentwo parted portions of the sheath sidewall as the sheath is retractedproximally and the sheath sidewall is parted.
 11. Apparatus fordelivering an implant, the apparatus comprising: a housing; an outersheath projecting distally away from the housing, the outer sheathhaving an outer sheath lumen; and an inner sheath projecting distallyaway from the housing at least partially within the outer sheath lumen,the inner sheath having an inner sheath lumen; wherein the implant is atleast partially positioned in the apparatus, and comprises an implantbody and a tether connected to the implant body; and wherein theapparatus is configured to advance the implant body distally within theinner sheath lumen without relative movement of the outer sheath and theinner sheath; wherein the tether has a first portion that extends fromthe implant body distally within the outer sheath and around a bearingsurface, where the tether changes direction, and extends backproximally, as a second portion, from the bearing surface along andwithin the inner sheath; and further comprising a reel that is coupledto the tether and configured to move the first tether portionproximally, and thereby draw the implant body distally along and withinthe outer sheath lumen.
 12. The apparatus of claim 11, wherein the outersheath is retractable proximally to expose the inner sheath.
 13. Theapparatus of claim 12, further comprising an outer sheath parting memberthat projects into the outer sheath lumen through an opening in asidewall of the outer sheath. wherein the outer sheath parting member isconfigured to part the sidewall of the outer sheath as the outer sheathis retracted proximally.
 14. The apparatus of claim 13, wherein theouter sheath parting member comprises a sharpened blade that cutsthrough the outer sheath sidewall as the outer sheath is retracted. 15.The apparatus of claim 13, wherein the outer sheath sidewall has a scoreline and the outer sheath parting member comprises a post or unsharpenedwedge that splits the outer sheath sidewall along the score line as theouter sheath is retracted.